Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements (Details)

v3.10.0.1
Fair Value Measurements (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Fair Value on Non-Recurring Basis      
Gross carrying value $ 751,955    
Amount of transfers of assets and liabilities measured on a recurring and non-recurring basis between Levels 1, 2 and 3 of the fair value hierarchy 0 $ 0 $ 0
Senior Notes 5.625%      
Fair Value on Non-Recurring Basis      
Gross carrying value 400,000    
Fair Value on Non-Recurring Basis | Level 1 fair value measurement | Senior Notes 5.625%      
Fair Value on Non-Recurring Basis      
Fair value $ 372,000